BT840F is the first module made with new Nordic nRF52840 Bluetooth chip. Before the first shipment on March 10th, 2017, we measured the transmission performance of new Bluetooth transceiver.

BT840F uses the same antenna circuit as that in BT832F, a production module. We set BT840F TX to +4 dBm, the same as maximum TC for BT832F.Data rate is set to 1Mbps.

Procedures for measuring BT832F ranges are described in BlueNor Mesh User Manual, can be downloaded from Download Module Document page.

Nordic has not released mesh stacks with S140 SoftDevice. BT840F ranges are measured with connection indication LED lights. One module is rotated by 30 degrees after each measurement. Twelve measurements are taken.

Average range between 2 BT832Fs is 273 meters
Average range between 2 BT840Fs is 234 meters

Average range of BT840F is about 86% of that of BT832F. Given the same + 4dBm TX power, BT840F receiver is 1.3 dB lower than that of BT832F. Or, nRF 52840 engineering sample has -94.7 dBm receiver sensitivity.

When production nRF52840 chip is used, range will be 14% longer.